This is true, and I don't understand why Linux doesn't have a smarter approach here. When a process suddenly starts using a lot of memory, and memory usage is approaching the limits of physical RAM, that process should be killed, rather than swapping out things like Gnome to make room for it.

Of course, that assumes a desktop environment. On a server, if a process starts using up a lot of memory, it's probably vitally important to keeping the (database|webserver) up, and should not be constrained in any way.

Which probably explains the situation that we're in.